title: BK viremia and polyomavirus nephropathy in 352 kidney transplants; risk factors and potential role of mTOR inhibition.
abstract: BACKGROUND
  Polyomavirus BK nephropathy (PyVAN) remains an important cause of early graft dysfunction and graft loss in kidney transplantation.
  
  
  METHODS
  In this retrospective, single centre cohort study we studied the incidence and outcome of BK viral infection in 352 patients transplanted in 2008-2011.
  
  
  RESULTS
  During follow-up viral replication was detected in 48 patients (13.6%); 22 patients (6.2%) had biopsy proven PyVAN.In multivariate logistic regression analyses risk factors for BK-viremia were lack of enrolment into randomized controlled trials (RCTs), biopsy proven acute rejections, cytomegaly virus (CMV) serostatus of both donor and recipient and previous transplantation.In patients without PyVAN reduction or switch of immunosuppression was associated with rapid viral clearance and stable graft function. In contrast, in most patients with PyVAN graft function deteriorated and 5 patients prematurely lost their allograft. Switch of immunosuppression to a low dose cyclosporine plus mTOR inhibitor based regimen in patients with PyVAN was safe, well tolerated and tended to be associated with a better short-term outcome in terms of graft function compared to reduction of existing immunosuppression alone.
  
  
  CONCLUSIONS
  With the lack of licensed anti-polyoma viral drugs reduction or conversion of immunosuppression remains the mainstay of therapy in patients with PyVAN. The combination of low dose cyclosporine plus mTOR inhibition appears to be safe and warrants further investigation.
authors.affiliation: Department of Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg, Ulmenweg 18, 91054, Erlangen, Germany. johannes.jacobi@uk-erlangen.de.
authors.forename: Johannes
authors.initials: J
authors.lastname: Jacobi
authors.forename: Antonina
authors.initials: A
authors.lastname: Prignitz
authors.forename: Maike
authors.initials: M
authors.lastname: Büttner
authors.forename: Klaus
authors.initials: K
authors.lastname: Korn
authors.forename: Alexander
authors.initials: A
authors.lastname: Weidemann
authors.forename: Karl F
authors.initials: KF
authors.lastname: Hilgers
authors.forename: Katharina
authors.initials: K
authors.lastname: Heller
authors.forename: Joachim
authors.initials: J
authors.lastname: Velden
authors.forename: Antje
authors.initials: A
authors.lastname: Knöll
authors.forename: Bernd
authors.initials: B
authors.lastname: Wullich
authors.forename: Christoph
authors.initials: C
authors.lastname: May
authors.forename: Kai-Uwe
authors.initials: KU
authors.lastname: Eckardt
authors.forename: Kerstin U
authors.initials: KU
authors.lastname: Amann
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000998:Antiviral Agents / Q000627:therapeutic use; D015984:Causality; D015897:Comorbidity; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D007674:Kidney Diseases / Q000453:epidemiology* / Q000517:prevention & control*; D016030:Kidney Transplantation / Q000009:adverse effects / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D027601:Polyomavirus Infections / Q000188:drug therapy* / Q000453:epidemiology*; D011183:Postoperative Complications / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors; D058570:TOR Serine-Threonine Kinases / Q000037:antagonists & inhibitors; D016896:Treatment Outcome; D014766:Viremia / Q000188:drug therapy* / Q000453:epidemiology*
chemical_list: D000998:Antiviral Agents; D007166:Immunosuppressive Agents; C546842:MTOR protein, human; D058570:TOR Serine-Threonine Kinases